EP3265658B1 - Manifold - Google Patents

Description

The invention relates to a manifold system for an internal combustion engine with a housing designed as a manifold with two inlet openings and with an outlet opening for the fluidic connection of two outlets of an internal combustion engine with an exhaust system. The housing has a maximum of two connection openings for connecting a double-shell inner LSI manifold.

LSI manifolds are air-gap-insulated manifolds with an inner shell and an outer shell, which can be installed separately as a separate component. Such a separate LSI manifold is always associated with only one engine-side exhaust port and does not form a manifold that sorts multiple engine-side exhaust ports.

The inner LSI manifold is the LSI manifold, which connects in the direction of flow to the manifold formed as a manifold. The outer LSI manifold refers to those LSI manifolds which connect in flow direction to the respective inner LSI manifold.

In this case, an inlet opening, outlet opening or connection opening is to be understood as meaning the respective end of the tubes or a housing which is connected by means of further connecting means, such as flanges or weld metal, to a further, other tube or housing.

It is already out of the EP 1 914 401 A2 a trained as manifold manifold housing for an internal combustion engine having a plurality of exhaust gas ducts, one of which an exhaust inlet opening end having in each case connectable to an outlet of the internal combustion engine and the other end is connected to a respective exhaust outlet opening having a collecting device. A first exhaust system is formed from the outlet of the internal combustion engine to the collecting device as a casting. At this collecting direction on both sides each include another manifold, merged over the two outlets of the internal combustion engine become. The two manifolds are designed as LSI manifold.

One of the exhaust gas guide identical construction with a total of three manifolds is in the DE 101 44 015 A1 described, in which the middle part is formed as a collecting housing double-walled air gap insulated from sheet metal.

The DE 39 25 802 A1 describes for connecting six outlets of an internal combustion engine with an exhaust system, a casting that serves as an adapter for six manifolds.

After DE 103 01 395 A1 is designed as a manifold bent double-walled housing, in which four connection openings are provided for the four outlets of the internal combustion engine.

In the DE 10 2011 106 242 A1 is described a system of single manifolds, which are inserted into each other in the number of outlets of the internal combustion engine.

The DE 10 2014 103 804 A1 describes identical inside and outside LSI manifolds.

The present invention has for its object to further develop an exhaust system such that simultaneously with a modular system, the sound of the exhaust noise and thus the exhaust system over several important speed ranges of the engine is optimized. Each average motor has between four and six outlets, which can be individually equipped by the modularity of the system. The geometry of the exhaust system is specifically tailored to the acoustics.

The object is achieved according to the invention in that at least one separate inner LSI manifold is provided with a connection opening, an inlet opening and an outlet opening which is shot with the outlet opening to the housing and at least a separate outer LSI manifold with an inlet opening and an outlet opening is provided with the outlet opening to the connection opening of the inner LSI manifold connected. All LSI manifolds are completely formed from sheet metal and each have a separate single or multi-part inner shell and a single or multi-part separate outer shell. All inner and outer LSI manifolds are identical or geometrically identical, with the inner LSI manifolds not identical in construction and not geometrically identical to the outer LSI manifolds.

As a separate LSI manifold manifold LSI manifold is called, which has its own inner shell and a separate outer shell. In contrast, multiple manifolds having a common outer or inner shell are not referred to separately according to this invention.

Due to the different geometry between inner and outer manifold, an advantageous resonance behavior is produced in the case of air gap-insulated bends. In particular, it has been found that reflecting surfaces which are oriented perpendicular to the flow direction adversely affect the resonance behavior, which is why the outer LSI bend is bent from its inlet opening to the outlet opening in its geometry deviating from the inner LSI bend.

The inner LSI manifold is connected with its outlet port directly to the manifold and connected via its port to the outlet port of an outer LSI manifold. This allows both sides of a manifold to connect only one LSI manifold and two LSI manifolds on both sides. The elbow system with two bends for a 4-cylinder engine can be extended to include two more identical bends to a manifold system for a 6-cylinder engine. The exhaust gas-conducting port openings, the inlet port and the outlet port are formed by the inner shell.

The different geometry has a particularly advantageous effect if, on the housing, the dimension of a distance A2 between one of the two inlet openings and the outlet opening is between 30 mm and 300 mm or between 50 mm and 120 mm. The advantageous acoustics are influenced by the frequencies which are decisive for such applications and / or their harmonics of very different orders. The wavelength of the relevant frequencies and / or their harmonics correlates as the relevant factor with the claimed distances. Although it was not possible to determine a strictly mathematically or physically derivable relationship between the distances and the harmonics, the advantages could be determined by several and sometimes complex test series.

Due to the different geometry of the subsequent to the manifold LSI manifold compared to the adjoining the housing LSI manifolds, an acoustics between the outlet and the manifold is achieved in particular in 6-cylinder inline engines, which sounds more harmonic compared to known manifold systems. This improvement is particularly advantageous when there is a certain amount of clearance A2 between one of the two inlet openings and the outlet opening, which varies between 50 mm and 120 mm, depending on the model of the manifold system. It was found that at smaller distances with the advantage of a small size, the sound behavior is extremely affected even with minor changes in the distances. An increase in the distance, however, causes advantageous sound properties.

Such manifold systems are preferably used in truck diesel engines or stationary diesel engines in which a turbocharger is subsequently arranged on the manifold. The designed as a central and bearing part housing provides the necessary statics for the connection of the turbocharger with the outlets on the motor housing.

For this purpose, it is particularly advantageous if the distance is dimensioned as a function of sound waves of the exhaust gas whose sound wavelength is calculated by n * A2 or 1 / n * A2, where n is an element of the natural numbers, but not zero. Here, A2 is the above-described measure of the distance between one of the two inlet openings and the outlet opening. L is the mean physical sound wave length, which is calculated from the quotient of propagation velocity C [m / s = meters / second] of the sound in the exhaust gas to the frequency f [1 / s = 1 / second = heart] of the wave. At an exhaust gas temperature of 700 ° C and a frequency of 300 Herz [Hz] results in a wavelength of about 750 mm. For example, this 300 Hz signal is generated by a 6-cylinder machine at 3000 rpm [rpm]. This low-frequency signal would be highlighted at a distance of 1/10 of the wavelength, ie with a distance A2 of 75 mm in the housing.

It can also be advantageous for the acoustics if the two inlet openings within the housing are fluidically and acoustically interchangeable with each other, whereby the harmonization is further increased, because a dynamic compensation can take place within the housing.

It may advantageously be provided that the manifold or the housing is formed as a one-piece casting. The vibration behavior of a casting is, as far as the acoustics of manifolds, compared to that of a sheet metal part very beneficial.

In cast housings, it may be advantageous if the two inlet openings in the housing are separated by a channel wall and two flow channels are formed through the channel wall, both flow channels open at the outlet opening at the end of the channel wall and the two flow channels via an upstream of the outlet opening in the channel wall provided leakage in the form of an opening or perforation fluidically and acoustically in exchange. As a result, the properties of an absolute group separation without any acoustic and fluid dynamic interaction and without any crosstalk between the two adjoining the flow channels manifold areas coupled with the properties without group separation with full acoustic and fluid dynamic interaction. By provided in the channel wall opening or perforation is the flow dynamic Interaction reduced, but at the same time the acoustic interaction is largely retained. The measure of the acoustic interaction varies both with the distance between one of the two inlet openings and the outlet opening and with the speed, because depending on the size of the opening as a forced leakage, the interaction decreases with increasing speed.

Of particular importance for the present invention may be when the manifold is formed from a low alloy gray cast iron having a carbon content of at least 1.00 mass% and further alloying additions having a respective average content of at most 50.00 mass%. Such called gray cast iron materials have an advantageous acoustic vibration behavior.

It can also be advantageous if the opening or the perforation has an overall cross section between 4 mm ² and 500 mm ² . For an advantageous resonance behavior, the leakage depends on the respective pipe cross-section.

Alternatively, it may be advantageous if the housing is completely formed from sheet metal, double-walled and air gap insulated with a one- or multi-part outer housing and a single or multi-part inner housing. The acoustic disadvantages of the sheet metal material can be compensated by a special shape of the outer housing. At the same time, the housings can be formed in one piece from folding shells or in several parts from an upper and a lower shell.

In sheet metal housings, it is advantageous if the inner housing is plugged together at the connection opening with the inner shell of the inner LSI bend at the outlet opening of the inner LSI bend and thereby between the inner housing and the inner shell leakage in the form of a joint gap with a mean width between 0 , 4 mm and 1.2 mm is formed.

It is also advantageous if the outer LSI manifolds have no connection opening and are arc-shaped. As a result, reflection surfaces are avoided, which extend at right angles to the flow direction.

Furthermore, it may be advantageous if the inner LSI manifold is connected to the housing by a material fit by welding or soldering or gluing. In particular, the welded joint in a manifold made of gray cast iron offers a very simple and inexpensive production method. It may also be advantageous for reasons of flexible mounting that the LSI manifold is connected to the manifold with a form-fitting with a union nut or with a V-band clamp or with a flange or with a clamping element.

Furthermore, it may be advantageous if the housing has only one connection opening, via which medium or directly two LSI manifolds are connected. This asymmetrical design has acoustic advantages over the symmetrical design in special applications.

Finally, it may be advantageous if the housing connects the outlet openings with a housing of a turbocharger and for this purpose forms a arranged between the engine block and the turbocharger supporting component.

Figur 1a

eine Schnittansicht eines als Sammelkrümmer ausgebildeten Gehäuses mit in Wechselwirkung stehenden Strömungskanälen;

Figur 1b

eine Seitenansicht des Sammelkrümmers gemäß Figur 1a;

Figur 2

eine Schnittansicht eines Krümmersystems mit einem Sammelkrümmer mit in Wechselwirkung stehenden Strömungskanälen und zwei inneren sowie zwei äußeren LSI-Krümmern;

Figur 3

eine Schnittansicht eines Krümmersystems mit einem Sammelkrümmer mit in Wechselwirkung stehenden Strömungskanälen mit einem inneren und einem äußeren LSI-Krümmer;

Figur 4

einen Sammelkrümmer, doppelwandig aus Blech;

Figur 5

eine Schnittansicht einer Flanschverbindung zwischen Sammelkrümmer und LSI-Krümmer;

Figur 6

eine Schnittansicht einer Verbindung zwischen Sammelkrümmer und LSI-Krümmer über ein Inlay im Sammelkrümmer;

Figur 7a

eine Ansicht eines Sammelkrümmers mit beidseitig angeordneter V-Band-Schelle;

Figur 7b

eine Schnittansicht einer V-Band-Schellen-Verbindung zwischen Sammelkrümmer und LSI-Krümmer;

Figur 8a

eine schematische Darstellung des Abstandes zwischen einer jeweiligen Einlassöffnung und der Auslassöffnung bei einem Sammelkrümmer in einer Ansicht von oben;

Figur 8b

eine schematische Darstellung des Abstandes zwischen einer jeweiligen Einlassöffnung und der Auslassöffnung bei einem Sammelkrümmer in einer Seitenansicht.

Further advantages and details of the invention are explained in the patent claims and in the description and illustrated in the figures. It shows:

FIG. 1a

a sectional view of a manifold designed as a housing with interacting flow channels;

FIG. 1b

a side view of the manifold according to FIG. 1a ;

FIG. 2

a sectional view of a manifold system with a manifold with interacting flow channels and two inner and two outer LSI manifolds;

FIG. 3

a sectional view of a manifold system with a manifold with interacting flow channels with an inner and an outer LSI manifold;

FIG. 4

a manifold, double-walled sheet metal;

FIG. 5

a sectional view of a flange connection between the manifold and LSI manifold;

FIG. 6

a sectional view of a connection between the manifold and LSI manifold via an inlay in the manifold;

Figure 7a

a view of a manifold with double-sided V-band clamp;

FIG. 7b

a sectional view of a V-band clamp connection between the manifold and LSI manifold;

FIG. 8a

a schematic representation of the distance between a respective inlet opening and the outlet opening at a manifold in a view from above;

FIG. 8b

a schematic representation of the distance between a respective inlet opening and the outlet opening in a manifold in a side view.

According to all embodiments, a housing 2 is provided, with two inlet openings 20, 21 for connecting the housing 2 to not shown outlets of an internal combustion engine and one to two connection openings 22, 23 for connecting in each case an LSI manifold (30-31). In terms of the cylinder order of an internal and external cylinder internal combustion engine, the respective "inner" LSI manifolds 31, 32 are between the housing 2 and an outer LSI manifold 30, 33 and the "outer" LSI manifolds 30, 33 are opposite the housing 2 arranged on the respective inner LSI manifold 31, 32.

In FIG. 1a is a sectional view of a manifold designed as a housing 2 with interacting flow channels 25, 26 shown. The housing 2 is formed from a gray cast iron and, in addition to the two inlet openings 20, 21 for connecting the housing 2 to not shown outlets of an internal combustion engine also has two connection openings 22, 23 for each inner LSI manifold 31, 32. Of the two inlet openings 20, 21, two flow channels 25, 26, which are arranged next to one another and are partially separated by way of a channel wall 27, extend within the housing 2 as far as in FIG FIG. 1b To improve the acoustic properties of the manifold 2, the two flow channels 25, 26 via a 51 formed as an opening leakage in the channel wall 27 with each other in interaction, which allows a so-called crosstalk.

At the in FIG. 2 illustrated embodiment of a manifold system 1, the housing 2 is not symmetrical, but has as well as the embodiment of the FIGS. 1a and 1b in addition to the two inlet openings 20, 21, two connection openings 23 for each an inner LSI manifold 31, 32. An outer LSI manifold 30, 33 with its outlet opening 37a adjoins the respective inner LSI manifold 31, 32 at its connection opening 38i. The inner LSI manifolds 31, 32 are all geometrically identical T-shaped with three openings 36i, 37i, 38i formed. The outer LSI manifolds 30, 33 are geometrically identically arcuately formed with only two openings 36a, 37a.

From the two inlet openings 20, 21 of the housing 2, two flow channels 25, 26 extend within the housing 2 to the outlet opening 24 of the housing 2. The two flow channels 25, 26 are also partially separated by a channel wall 27 in their interaction. The illustrated with arrows average length of the two flow channels 25, 26 corresponds to one of the FIGS. 8a and 8b closer described distance A2 between the respective inlet opening 20, 21 and the outlet opening 24. In this embodiment, the distances A2 differ by a factor of 1.6.

In FIG. 3 shows a housing 2 for a manifold system 1 for an internal combustion engine with four cylinders arranged in series. The housing 2 has only one connection opening 22 for an inner LSI manifold 31 with a T-shaped geometry. To this inner LSI manifold 31 is connected an outer arcuate LSI manifold 30. In this case 2, no reduction in the interaction between the two flow channels 25, 26 is provided by a channel wall 27.

In FIG. 4 an air gap insulated housing 2 is shown, which is designed as a manifold. The housing 2 has an outer housing 28 and two inner housings 29 integrated in the outer housing 28. The housing 2 is designed as a supporting component and connects the outlets of the engine block, not shown, with a housing, not shown, of a turbocharger. To the housing 2 close on both sides not shown inner LSI manifold, which have no supporting or statically relevant function.

All LSI elbows 30 have, as air gap-insulated elbows, an inner shell 34i, 34a and an outer shell 35i, 35a surrounding the inner shell 34i, 34a. At least at the respective inlet openings 36i, 36a, the respective inner shell 34i, 34a and the respective outer shell 35i, 35a are flush with one another in one of the directions of flow.

By the connector between the inner shells 34i of the subsequent inner LSI manifolds 31, 32 and the inner housing 29, a joint gap 52 is formed, which also generates a leak. The width 53 of the joining gap 52 varies, for example, with the diameter of the inner housing 29 and is between 0.4 mm and 1.2 mm. Due to this leakage, the crosstalk between the two inner housings 29 is made possible also in this embodiment. The sealing of the respective inner LSI manifold 31-32 to the housing 2 is via the connection of the outer shell 35i reaches the housing 2. The connection between the housing 2 and the outer shell of the respective LSI manifold 31, 32 is preferably formed as a welded joint. Alternatively, according to the Figures 5-7b a compound as a flange 7 or inlay 8 or V-band clamp 6 is provided.

The inner and outer LSI manifolds 30-33 shown in the embodiments are formed of sheet metal. LSI sheet metal manifolds show a favorable resonance behavior. Due to the different shape of the inner and outer LSI manifold 30-33, the acoustic properties are improved in particular operating points of the internal combustion engine, because the vibration and resonance behavior harmonizes.

The in the FIGS. 8a and 8b The illustrated distance A2 between the respective inlet opening 20, 21 and the outlet opening 24 is also dependent on the size ratios of the respective diameters De of the inlet openings 20, 21 to the diameters Da of the outlet opening 24. For an optimal acoustic adaptation to the most important operating points of the internal combustion engine, in particular with respect to the speeds relevant for the most important load ranges, thus the distances A2, the diameter ratios De, Da and the construction equality of the corresponding openings of the LSI manifold 30-33 are relevant.

Claims (12)

1. A manifold system (1) for an internal combustion engine, having

   a) a housing (2), which is designed as a collecting manifold and which has two inlet openings (20, 21) and an outlet opening (24) for the fluidic connection of two outlets of an internal combustion engine to an exhaust system, and

   b) at most two connection openings (22, 23) provided on the housing (2) for connecting a double-shell inner air-gap-insulated manifold (31, 32),
   characterised in that

   c) at least one separate inner air-gap-insulated manifold (31, 32) having a connection opening (38i), an inlet opening (36i) and an outlet opening (37i) is provided, which is connected to the housing (2) by means of the outlet opening (37i), and

   d) at least one separate outer air-gap-insulated manifold (30, 33) having an inlet opening (36a) and an outlet opening (37a) is provided, which is connected to the connection opening (38i) of the inner air-gap-insulated manifold (31, 32) by means of the outlet opening (37a), and

   e) all air-gap-insulated manifolds (30-33) are completely formed of sheet metal, and each air-gap-insulated manifold has a separate one- or multi-part inner shell (34i, 34a) and a one- or multi-part separate outer shell (35i, 35a), and

   f) all inner air-gap-insulated manifolds (31, 32) are structurally or geometrically identical and all outer air-gap-insulated manifolds (30, 33) are structurally or geometrically identical,

   g) wherein the inner air-gap-insulated manifolds (31, 32) are not structurally identical and not geometrically identical to the outer air-gap-insulated manifolds (30, 33).
2. The manifold system (1) according to Claim 1,
   characterised in that
   the dimension of a distance (A2) on the housing (2) between one of the two inlet openings (20, 21) and the outlet opening (24) is between 30 mm and 300 mm or between 50 mm and 120 mm.
3. The manifold system (1) according to Claim 1 or 2,
   characterised in that
   the two inlet openings (20, 21) are in a fluidic and acoustic exchange with each other within the housing (2).
4. The manifold system (1) according to any one of the preceding claims,
   characterised in that
   the housing (2) is designed as a one-part casting.
5. The manifold system (1) according to Claim 4,
   characterised in that
   the two inlet openings (20, 21) in the housing (2) are separated by a duct wall (27) and two flow ducts (25, 26) are formed by the duct wall (27), wherein both flow ducts (25, 26) open out at the outlet opening (24) at the end of the duct wall (27) and the two flow ducts (25, 26) are in a fluidic and acoustic exchange via a leakage in the form of an opening (51) or perforation provided upstream of the outlet opening (24) in the duct wall (27).
6. The manifold system (1) according to Claim 5,
   characterised in that
   the opening (51) or the perforation has a total cross-section between 4 mm² and 500 mm².
7. The manifold system (1) according to any one of Claims 1 to 3,
   characterised in that
   the housing (2) is completely formed of sheet metal, is double-walled as well as air-gap insulated with a one- or multi-part outer housing (28) and a one- or multi-part inner housing (29).
8. The manifold system (1) according to Claim 7,
   characterised in that
   the inner housing (29) at the connection openings (22, 23) is mated with the inner shell (34i) of the inner air-gap-insulated manifold (31, 32) at the outlet opening (37i) of the inner air-gap-insulated manifold (31, 32) and a leakage in the form of a joint gap (52) having an average width (53) between 0.4 mm and 1.2 mm is thereby formed between the inner housing (29) and the inner shell (34i).
9. The manifold system (1) according to any one of the preceding claims,
   characterised in that
   the outer air-gap-insulated manifolds (30, 33) do not have a connection opening and are configured in the form of an arc.
10. The manifold system (1) according to any one of the preceding claims,
    characterised in that
    the housing (2) has only one connection opening (22).
11. The manifold system (1) according to any one of the preceding claims,
    characterised in that
    the housing (2) connects the outlet openings (37i, 37a) to a housing of a turbocharger and, for this purpose, forms a load-bearing component arranged between the engine block and the turbocharger.
12. A system consisting of a manifold system (1) according to any one of the preceding claims and an internal combustion engine.

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